Search for the doubly charmed baryon \( \Xi_{cc}^{+} \)

Abstract A search for the doubly charmed baryon \( \Xi_{cc}^{+} \) in the decay mode \( \Xi_{cc}^{+}\to \Lambda_c^{+}{K^{-}}{\pi^{+}} \) is performed with a data sample, corresponding to an integrated luminosity of 0.65 fb−1, of pp collisions recorded at a centre-of-mass energy of 7 TeV. No significant signal is found in the mass range 3300-3800 MeV/c 2. Upper limits at the 95% confidence level on the ratio of the \( \Xi_{cc}^{+} \) production cross-section times branching fraction to that of the \( \Lambda_c^{+} \), R, are given as a function of the \( \Xi_{cc}^{+} \) mass and lifetime. The largest upper limits range from R < 1.5 × 10−2 for a lifetime of 100 fs to R < 3.9 × 10−4 for a lifetime of 400 fs.